The oxygen in compressed air permeates through the membrane, reducing the pre charge pressure. During normal function, oxygen oxidizes the membrane in the vessel, causing under-inflation and deterioration of the rubber.

Dry nitrogen by comparison maintains proper inflation pressure longer, will not corrode the inside of the vessel and extends valve and expansion vessel life.

Industry research indicates that oxidative aging is one of the primary causes of decreased vessel life. Oxidative aging that is caused by the diffusion of oxygen from the pressurized air cavity of the vessel to the outside atmosphere. Tests have shown that if vessels are inflated with nitrogen, there is a significant reduction in failure.